Will A 1LE (18 gallon ) fuel tank fit in my 89 formula that came with a 15 gallon tank?

Thanks

 

If you find an 18 gallon gas tank. Let us know. Take pictures and post part numbers too, a lot of us would think it was cool.

Yes that was sarcasm. It's a myth. Noone has ever produced those 2 simple pieces of info. Another myth is the baffles. All later thirdgens have baffles fuel tanks. Even TBI RS's and 6 poppers. Still around 15.5 gallons w/ the electric pump in it.

 

For some reason I have a 12 gallon tank in my car.
Gas Gauge works perfect, when it is on E, it is about to run out of gas.
I once had the car run out of gas at the shop when they were tuning my rebuilt carb, they put in one gallon, and I drove to the gas station afterwards and put in almost 12 gallons and it was overflowing. Tank is not dented.

Anyone else have a tiny tank in their 3rd gen?

 

Ed: It's true, all thirdgen gas tanks have the metal baffles. But there's a plastic bowl inside the tank that's only on the higher trim-level cars until 90 or 91, then from there to 92 all thirgens had the larger bowl. The bowl has higher sides that helped prevent fuel starvation on hard cornering. And I do have pics of that. The crappy version had a bowl about 1 to 1 1/2 inches high, while the better version had 4 or 5 inch high walls with only a slot cut out on the front for the sender assembly to slide down into the bowl.

Here's the crap version (this one out of an 89RS):


And here's the version found in Z28s and all 90-92 models (this one out of a 91RS):

 

Zepher, the only thing I can think of is that your sender assembly is bent or somehow different so that the feed is sitting higher than it should and not picking up the last gallon or so that it should. I seriously doubt you actually have a smaller tank.

 

One day when I have the tank off the car I am going to measure the exact fluid capacity.